'My mind is so clouded right now,' says mother of Tanisha Peterson, 22. 'We loved her so much'

Tristan Dave-Lawrence (left), Cade Lavallee (centre) and Tanisha Peterson (right) were found unresponsive in a car near Conklin, Alberta on Tuesday morning. (Supplied)

All three people found dead in a parked car in northern Alberta were killed by carbon monoxide poisoning, the families have confirmed.

Sonya Peterson told CBC News Thursday that a medical examiner said her daughter, 22-year-old Tanisha Peterson, died from carbon monoxide poisoning after she was found unresponsive in a vehicle just outside Conklin, Alta.

"My head is so clouded right now," Peterson said. "We loved her so much."

'When she walked into a barn, her whole attitude changed'

Tanisha Peterson was a "spunky, full of life" young adult who was "very true to herself," her mother said.

"She always did what she wanted, no matter what people thought."

Peterson's real passion in life was horse jumping.

"She was an anxious child but when she walked into a barn … her whole attitude changed," her mother said.

Tanisha Peterson was in Conklin to 'get her ducks in a row' before studying to become an equine physiotherapist. (Sonya Peterson)

The young girl, who lived in Camrose, Alta., dreamed of a life doing what she loved, until she suffered from an ankle injury and required surgery. The damage was so extensive, her mother said, that she was unable to continue riding horses competitively.

Crushed, Tanisha moved to Conklin, where she worked at Karen's Restaurant and Lounge as a server with her friend Tristan Dave-Lawrence. She was there to make more money and "get her ducks in a row" before studying to become an equine physiotherapist, her mother said.

Extended family in Nova Scotia

Sonya Peterson and her husband uprooted the family from their hometown of Brookfield, N.S., to Alberta 10 years ago when their forestry business took a dive.

Most of their extended family still lives in their hometown, something Sonya said is "really hard" for her and her family during this time.

Tanisha Peterson leaves behind a brother and a sister, who are not taking the loss of their sibling well.

Tanisha Peterson (right) pictured with her siblings. (Sonya Peterson)

"I can't believe I lost my big sister ... this is all so surreal," her sister Emma Peterson wrote in a Facebook post.

"I love you Tanisha. Forever and always."

RCMP have not confirmed cause of death

Tristan Dave-Lawrence, 21, and Cade Lavallee, 29, were also found dead in the parked vehicle on the Lagoon Access Road just outside Conklin, a small hamlet 150 kilometres south of Fort McMurray on Highway 881.

All three young adults were pronounced dead on scene after RCMP tried to provide first aid.

The families of both other victims told CBC News that their loved ones had died from inhaling high levels of carbon monoxide.

Wood Buffalo RCMP are waiting for autopsy results and a vehicle inspection before confirming the cause of death.

RCMP Victim Services is offering assistance to family, friends and witnesses in the area. Anyone in need of assistance is encouraged to contact the agency.

"Our thoughts and sympathies go out to the family, friends, and anyone who has been impacted by this incident," Wood Buffalo RCMP said in a statement.